Separation of tall oil into components



Nov. 28, 1 9.44. F. w.. ADAMS 2,363.925

- SEPARATION OF TALL OIL INTO COMPONENTS Filed Dec. 19, 1941 RH FFIIIVHTE I z! WET 1-,. ETA/7? Z, Earn/w; T

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' PHT A/HPIYTHH I J ,4 y I T444 .0 1. AND 3 WET FTHEK q/E-r GZVCOL ETA/E1? 0F 62 YCOL 27 1 s? i as flFFl/VHTE k Lz 37 AMP 4 AMP/1 THH 2 zx-nencr INVENTOR; FREDERICK Milan/-15 HT'TOR/VE'K Patented Nov. 28, 19%

" attests SEPARATION OF TALL OIL INTO COMPONENTS Frederick W. Adams. Pittsburgh, Pa, assignor to Pittsburgh Plate Glass Company, Allegheny County, Pa.,' a corporation of Pennsylvania Application December 19, 1941, Serial No. 423,597

' "40mins. (o1. zoo-91.5)

The present invention relates to the treatment oi tall oil and it has particular relation to treatment of tall oil for purposes of separating it into fractions containing certain components of the oil in higher'concentrations than occur in the original oil.

One object or the invention is to separate tall .011 into fractions comprising certain components of the oil in such proportions as to be substantially more valuable for certain commercial uses than the original oil.

A second object of the invention is to provide a process of the foregoing. type which is simple and economical to operate.

These and other objects of the invention will be apparent from consideration or the followin specification and the appended claims.-

In the manufacture of paper pulp by the sulfate process an oily material termed "tall oil" is liberated and collected. The amount'obtained constitutes many thousands of tons each year. In composition the oil consists primarily of:

Per cent Fatty acids 50to 60 Resin acids 34 to 48 Non-acids .6 to

Heretoi'ore, the tall oil has had but little commercial application and its value has been very slight. However, itis recognized that at least a "P rtion of the components, it they could be ob- For a better understanding of the invention reference may be had to the accompanying drawing in which Figures 1 and 2 diagrammatically illustrate preferred systems applicable to the practice of the invention. i

In the drawing like numerals refer to like parts throughout. As shown in Figure 1, a column Ill suitable for countercurrent extraction operations and which may be filled with a suitable packing, such as Raschig rings designed to promote thorough intermingling and contact of the liquids, is provided at'its upper extremity with an inlet indicated by arrow I I. Throush'this inlet, a polar solvent or polar solvent mixture, such as the monoethyl ether of ethylene glycol or a mixture of water and methyl or ethyl alcohol-or water and acetone or furfural' saturated with tained in sumciently pure form, would be highly valuable for many'industrial applications. For

example, the free fatty acids would be excellent for use as modifiers in alkyd resins and other resinous products. The resin acids at present perhaps are of less commercial value than the fatty acids, but they are'sultable for use in the production of soaps and perhaps as modifiers in certain types of alkyd resins. Of .course other applications are possible. The non-acids in the tall oil apparently include sterols, many of which,

water may be introduced. A hydrocarbon solvent such as solvent naphtha is introduced at the" bottom of the column through an inlet indicated by the arrow I2. The tall oil to be extracted is introduced, as indicated at I3, at an intermediate zone in the system preferably about midway between theinlets for the solvents. It may be admixed with several times its own volume of the polar solvent before it is so introduced.

The rafllnate fraction comprising primarily the hydrocarbonand such components of the tall oil as are soluble therein, e. g., fattyacidsysterols' and other unsaponifiable matter, is drawn oil at the top of the column to the line indicated by the arrow It. At the bottom of the column the extract, including polar solvent and a fraction rich in resin acids, passes out through a conduit indicated by the arrow IS.

The extract phase is carried by the line I6 to a second column I1 and introduced into the top of the latter. Hydrocarbon, such as solvent naphtha, is introduced at the bottom of this column by when in sufilciently pure form, are highly valuable.

The present invention contemplates the simultaneous extraction of the oil with an active polar solvent having an aflinity tor the resin coinponents and a hydrocarbon solvent which has a preference for the tree iatty acids and the nonacid components and is relatively immiscible with the polar solvent and of a different specific gravity. As one feature, the extract phase com. PM the polar solvent is further extracted 'countercurrently with addltlonalhydrocarbon in order to obtain a rafllnite rich in a feed line I8. The extract phase containing a fraction of the tall oil rich in resin acids and low in fatty acids and sterols passes out at the bottom through the conduit I9. The raflinate from the second column consisting primarily of naphtha containing a fraction of the tall oil very rich-in fatty acids along with some resin acids and sterols passes out through the line indicated by the In the operation of the foregoing apparatus it is preferred that the ratio of polar solvent, such as the wetether of ethylene glycol, be relatively high as compared to the tall oil and the naphtha.

The naphtha ratio may be substantially less in quantity than the tall oil and may be as low as tree Iattyacida 30 01" per cent of theitall oil'content'. The tall prises flowing naphtha oil introduced into the intermediate portion of the column It may be dissolved in a large amount of solvent. The ratio of the ingredients, for example, may comprise 1297 parts of tall oil dissolved in about 14,443 parts of the methyl ether of ethylene glycol containing about 8to 12 per-- cent of water. A further feed of the methyl ether of ethylene glycol containing about 8 to 12 percent of water and in the ratio of about 4,675 parts a maybe introduced into the top of the column it). About 847 parts of naphtha is introduced at the bottom of the column Ill. When the system is so passed into the column H where it may be ex tracted with a high ratio of naphtha. The system is preferably operated at a temperature of about 24 (2., but temperatures C/or more higher or lower are, also, contemplated.

In Figure 2 is disclosed a three column system which in principle of operation is similar to that disclosed in Figure 1. It includes two columns 25 and 26 that function similarly to column ill. The tall oil, preferably in admixture with a polar solvent, is fed, as indicated at 21, into thetop of column 25. Naphtha or its equivalent is fed in near the bottom of the column, as indicated at 28.

The extract of the polar solvent containing much of the free resin acids in solution passes out as indicated at 29 from the lower portion of the column. Its further treatment will be later described.

The raflinate phase comprising naphtha and a fraction rich in sterols and fatty acids is taken from the upper portion of the column as indicated at 3|. It is fed to the lower portion of the column 26 and flows upwardly in the latter counterascaoao venlt action for fatty acids-into one end of a solvent system and a mixture of water andthe methyl ether of ethylene glycol having a preferential solvent action .for resin ac'idsinto the other end. of said system and flowing the two solvents mutually countercurrently through the system, introducing tall oil at approximately mid portion of the system, removing the naphtha saturated with a fraction of .tall oil which" is enriched in fatty acids and'impoverishedin resin acids at the end of the system contiguous to the inlet for methyl ether of ethylene glycol and withdrawing the methyl ether of etlwlene' glycol saturated with the fraction of tall oil enriched in resin acids and impoverished in fatty acids at the other end of the system, (then countercurrently extracting the methyl ether of ethylene glycol andthe dissolved tall oil fraction with separate portions of naphtha to form a new fraction of tall oil, the one dissolved in the naphtha being further enriched in fatty acids and impoverished in resin acids. v

2. .A method of treating tall oil, which comprises flowing naphtha having a. preferential solvent action for fatty acids of tall oil into one end of a solvent system and flowing a solvent which is immiscible with and of a different density-from currently to a flow of polar solvent, e. g., wet ether.

of ethylene glycol introduced into the upper part of the column at 32. The rafllnate from the upper part of this second-column and consisting mainly of fatty acids and non-saponifiables' in the naphgtha is drawn off as indicated at 33. The extract rich in resin acids and containing some fatty acids is recycled through line 34 .to the top of column 25 for further extraction with naphtha.

The extract phase passing from column 25" through line 29 is reextracted in column 36 with additional naphtha introduced at the bottom of the column through line 31. The second ramnaite, consisting mainly of naphtha in which is dissolved a fraction rich in free fatty acids, is drawn on from near the top of the column as indicated at 38, while the extract of polar solvent, in whlch is dissolved a fraction rich in resin acids, is drawn off at the bottom of the column as indicated at 89. The solvents'may be recovered from all of the fractions by evaporation or by crystallization methods.

It isto be noted that according to the present method a'ramnate fraction, dissolved in a small amount of naphtha or other appropriate non- Polar solvent, isextracted with a very large ratio of polar solvent. This fraction is very rich-in sterols and also includes a high percenta e of free fatty acids. It is drawn ofl through lines M or 33.

What I claim is:

l. A method of treating tall oil, which comhaving a preferential solthe naphtha and having a preferential solvent action for the resin acids of tall oil into the other end-of said system and flowing the-two solvents mutually countercurrently through'the system,

tion of the system, removing thenaphtha saturated with a fraction of tall oil which is enriched acids at .the end of the system contiguous to the inlet for solvent for fatty acids, then counterc'urrently extracting the solvent for res'in acids and the dissolved tall oil fraction therein with a separate portion of the solvent for fatty acids, to form two new fractions of tallnil in mutually immiscible solvents, the one dissolved in the naphtha bein further enriched infatty acids and impoverished in resin acids.

3; A method of'treating. tall oil,'which comprises flowing naphtha having a preferential solvent action for fatty acids of .tall 011 into one end ,of a solvent system and flowing a solvent which is V immiscible with and of a different density from the naphtha and having a preferential solvent action for the resin acids of tail oil into the other end of-said system and flowing thetwo solvents [mutually countercurrently through the'syste'm,

introducing tall 011 at approximately the mid portion of thesystem, removing the naphtha sat urated with a fraction of tall oil which is enriched in fatty acids and impoverished in resin acids at the end of the system contiguous to the inlet for the solvent for resin acids, withdrawing the solvent having preferential solvent action for resin acids saturated with a fraction of tall oil enriched in said resin acidsand impoverished in fatty acids at the endof the system contiguous to the inlet 7 for solvent for fatty acids, then countercurrently extracting the solvent for resin acids and the dis-. solved tall oil fraction therein with a separate portion of the solvent for. fatty acids, to form'two new fractions of tall oil in mutually immiscible solvents, the one dissolved in the naphtha being further enriched in fatty acids andimpove'rished in resin acids. the ratio of solvent for resin acids introducing tall oil at approximately the mid por-' escapes the end of the system contiguous to the inlet :6:

' to naphtha being so'sreat that most 0! the the olvent for resin acids, withdrawing the solon passes out in the extract and a rafnnate greatly enriched in non-acid constituents of the tall oil isobtained. t v v 4. A method of treating tail oil, which com prises flowing naphtha having a preferential solvent action for-fatty acids or tall oil into one end or a solvent system and flowing a solvent, which is immiscible with and of a diiierent density from the naphtha and having a preferential solvent action for theresin acids of tall oil into the other end of said system and flowing the two solvents mutually .countercurrently through the system,-

intreducing tall oil at approximately the mid portion of the system, removing the naphtha satmated with a fractionof tall oil which is enriched in fatty acids and impoverished in resin acids at vent having preferential solvent action for resin acids saturated with a traction of tall 011 enriched in said resin acids and impoverished in fatty acids at the en'doi the system contiguous to the inlet fox-solvent for fatty acids, then countercurrently extracting the solvent for resin acids and the dissolved tall 011 fraction therein with a separate portion of the solvent for fatty acids, to-

iorm two'new fractions of tall oil in mutuallyimmiscible solvents, the one dissolvedin the naphthe. being'further enriched in fatty acids and im-,

-pove'rished in resin acids, the tall oil being admixed with solvent tor resin acids before itis introduced into the system. I

' FREDERICK 

